Radioactive Seed Implants for Prostate Cancer

Introduction:

Radiation therapy, known as prostate seed implantation (PSI), involves implanting radioactive seeds inside the prostate. PSI exposes the prostate gland and, occasionally, the seminal vesicles, which are located on either side of the prostate gland, to a high radiation dosage.

What Is the Process for Implanting Radioactive Seeds?

One type of radiation treatment for prostate cancer is permanent radioactive seed implantation. This treatment may be called "brachytherapy" or "internal radiation therapy." Using ultrasound guidance, radioactive seeds (iodine-125 or I-125) are implanted into the prostate gland during the surgery. A computer-generated treatment plan customized for each patient dictates the quantity and placement of seeds.

Typically, 100 seeds are inserted. After roughly ten months, the implants become biologically inert or dormant and stay in place indefinitely. This approach allows the prostate to receive a high dosage of radiation with little harm to the surrounding tissues. Implanting radioactive seeds is an outpatient surgery. Convenience is a key benefit of this treatment option over external radiation, which calls for daily treatments for up to seven or seven and a half weeks.

For Whom Is This Method Appropriate?

Since permanent implants are low-energy devices, their ability to penetrate tissue is restricted. A well-executed implant addresses the prostate as well as a few millimeters of nearby tissue. Patients with cancer in or near the prostate are the greatest candidates for this surgery. This procedure is not acceptable for patients whose prostate cancer has spread to adjacent regions such as the bladder or rectum.

What Are the Types of Prostate Brachytherapy?

Procedures for prostate brachytherapy differ depending on the type:

1. High-Dose Rate Brachytherapy (HDR): A few minutes after the radioactive sources are inserted, HDR brachytherapy, a transient form of prostate brachytherapy, administers a high dosage of radiation to the prostate gland. Treatment often takes place over several sessions.

2. Low-Dose Rate Brachytherapy (LDR): Permanent prostate brachytherapy, or LDR brachytherapy, involves implanting radioactive seeds in the prostate gland over an extended period. These seeds gradually release radiation over several months.

What Happens When a Radioactive Seed Implant Is Performed?

• The process takes around 90 minutes to complete. On most days, patients return home. A urologist and radiation oncologist carry out the procedure. Both doctors actively handle every facet of the implantation, from planning to post-operative care. The radiation oncologist plants the radioactive seeds as the urologist guides the ultrasound. The radioactive seed insertion and treatment planning are completed concurrently with the prostate ultrasonography.

• Following spinal or general anesthesia, the legs are gently lifted and cushioned. To take images of the prostate, an ultrasonography probe is placed into the rectum. The probe stays in position the entire time.

• A personalized treatment plan is created using the ultrasound images. Subsequently, the prescribed quantity of needles is filled with the radioactive seeds. Using continuous ultrasound guidance, each needle is put into the prostate through the skin in the perineum (the region between the anus and the base of the scrotum) in a particular order. The seeds within the needle are released as soon as precise needle placement is verified. This process is repeated until all of the radioactive seeds have been inserted. There is no need for any cutting or surgical incisions. A catheter may be inserted into the bladder briefly to guarantee adequate drainage in the event of blood in the urine. Every patient is instructed on how to catheterize themselves at home in case it becomes necessary to empty their bladder of pee.

What Are the Outcomes of Operations Involving Radioactive Seed Implants?

The prostate cancer risk group and the success type being measured determine the success rate. Prostate-specific antigen (PSA) measurements following therapy are associated with the most frequent measurement. The Gleason score is the system used for grading. The five-year success rates for the different risk groups using this strategy are:

• 95 percent of samples are low-risk (PSA < 10 ng/mL and a Gleason score < 7).

• PSA < 10 ng/mL and a Gleason score of 7, or PSA 10 ng/mL to 20 ng/ml with a Gleason score of 6 = 90 percent, corresponding to the intermediate-risk category.

• 74 percent are classified as high-risk (PSA > 20 ng/mL, Gleason score > 7, and any PSA).

• Understanding that these figures greatly rely on how often the PSA test is taken following treatment is crucial. After therapy, PSA testing ought to be conducted every six months. It is necessary to confirm that the PSA tests are being drawn at least this frequently in reports of comparable rates from other sources to draw comparisons.

What Are the Side Effects?

Side effects from prostate brachytherapy could include:

1. Difficulty beginning to urinate.

2. Having frequent, overwhelming urges to urinate.

3. Discomfort or pain during urination.

4. Having a nighttime urination.

5. Urine containing blood.

6. Being unable to empty the bladder fully.

7. Erectile dysfunction.

8. Bleeding in the lower abdomen.

9. Stool containing blood.

10. Urgent bowel movements.

11. Increased frequency of bowel motions.

Medication is a common tool used by doctors to lessen therapeutic adverse effects. Prostate brachytherapy has many negative effects that fade with time.

What Are the Uncommon Issues?

Prostate brachytherapy can have a few major side effects, albeit these are uncommon. Among them are:

1. Urethral narrowing.

2. Abnormal fistula (opening) in the rectum wall.

3. Radiation-induced cancer of the bladder or rectum.

What Other Information Is Crucial About the Radioactive Seed Implant Process?

For the first two months following the treatment, small children should not have more than 20 minutes of close, extended contact (sitting on the lap). One can safely sleep in the same bed if one’s spouse or partner is not pregnant. If the spouse or partner is pregnant, separate sleeping arrangements will be required for two months. If the patient has more questions, contact a radiation oncologist or urologist.

Conclusion:

The patient might have follow-up blood tests to check the amount of prostate-specific antigen (PSA) in blood after prostate brachytherapy. A doctor may be able to determine the effectiveness of treatment using these tests. After prostate brachytherapy, it is common for PSA levels to abruptly increase before declining once more (a phenomenon known as "PSA bounce"). Doctors will likely keep an eye on the PSA level to make sure it does not keep rising. Find out from the doctor when one should expect to know if therapy is affecting prostate cancer.